谷歌搜索营销人员on their toes withfrequent updatesto itssearch algorithms.

The latest major update, dubbed "Fred," affected some sites more than others. Inthis infographic, digital marketing agency180fusiondecodes what that means for marketers.

For starters, the infographic explains that the update "mostly targets sites with ad-focused content that prioritize revenue above helping the users." So, sites that use multiple affiliate links, for example, likely registered a downturn in traffic after the update went into effect.

It also means that sites that offer valuable content with unobtrusive ads may have had an increase in site traffic, the infographic says.

For more details on Fred and who was affected, check out the full infographic. Tap or click to see a larger version.